Numerous types of biopsy forceps have been developed for in vivo medical diagnosis and treatment of various conditions. Such devices are designed for sampling tissue within the body, for example in endoscopic, laparoscopic and vascular procedures to retrieve biopsy samples for analysis and identification of tissue types. These biopsy forceps devices generally include small cutting jaws at the distal end, operated remotely from the proximal end after the distal end of the device has been positioned or navigated to the site of interest.
One difficulty in using prior art biopsy forceps devices is in knowing for certain the exact positioning of the distal tip, in relation to the suspected disease area, especially when the area of interest is very small. Another difficulty of prior art biopsy forceps in combination with other endoscopic accessories is the exact positioning of both instruments. Various types of optical catheters or probes have been developed for use in locating or identifying sites within the body. A method of diagnosing in vivo using an optical guidewire is disclosed in U.S. Pat. No. 5,439,000, assigned to SpectraScience, Inc. An apparatus and method for identifying and obtaining a biopsy sample is disclosed in pending U.S. application Ser. Nos. 08/643,912 and 08/644,080 licensed and assigned, respectively, to SpectraScience, Inc. The applications are entitled "Optical Biopsy Forceps and Method of Diagnosing Tissue" and "Optical Biopsy Forceps," respectively.
One type of prior art system for internal biopsy uses an optical catheter to locate the site, followed by replacement of the optical catheter with a biopsy forceps for taking a tissue sample. However, this can result in errors and uncertainties in the final placement of the biopsy jaws with respect to a previously identified small structure or targeted area since the exact site identified by the optical catheter is not treated with the biopsy forceps or other instruments to treat the site.
Other prior art systems have been proposed which use optical viewing or imaging and a cutting device in the same device, to visually locate and then biopsy a suspected area. However, such devices have been hampered by their thickness which is needed to accommodate the imaging system and the cutting actuation system, and which precludes their use in very small areas. Another shortcoming of such prior art systems is the offset or `parallax` between the viewing axis or the imaging system and the cutting position of the biopsy jaws, such that the biopsy sample actually is taken from a zone slightly displaced from the zone being viewed by the optics. This can result in a loss of accuracy in the case of very small structures of interest.
Another difficulty in conventional devices is accessing the area from which the biopsy sample is to be taken. Often the area to be sampled requires treatment before the sample is taken. An optical catheter is used to locate the biopsy site, followed by replacement of the optical catheter with a medical instrument for treating the area. The instrument is removed, and biopsy forceps is inserted for taking a biopsy sample. However, this can result in errors and uncertainties in the final placement of the biopsy jaws with respect to a previously identified small structure or biopsy area.
Other biopsy devices allow for a biopsy sample to be pierced with a spike before the biopsy sample is taken. However, these devices are limited to the fixed instrument disposed within the forceps. If additional instruments and treatment is necessary for the biopsy area, the biopsy device must be removed from the body, and a different device inserted into the body. Removing the device to insert another poses additional problems in that the exact biopsy location will not be treated.
Accordingly, a better way to treat biopsy areas is needed. What is further needed is a device to accommodate multiple methods of treatment for an exact biopsy area. What is also needed is a better way to obtain a biopsy sample.